1. Field of the Invention
This invention relates generally to semiconductor devices, and specifically, to package structures and methods for fabricating the same.
2. Description of the Related Art
Semiconductor components include external contacts that allow electrical connections to be made from the outside to the integrated circuits contained in the semiconductor components. A semiconductor die, for example, includes patterns of bond pads formed on the face of the die. Semiconductor packages, such as chip scale packages, also include external contacts. Typically, a component includes only one set of external contacts on either the face side (circuit side) or the back side of the component. However, it is sometimes necessary for a component to have external contacts on both sides.
In semiconductor technology, a through-silicon via, also known as a through-substrate via, is a conductive feature formed in a semiconductor substrate (wafer or die) to electrically connect external contacts from both sides. The TSV feature vertically passes through the semiconductor substrate, providing for stacked wafer/die packaging methods and allowing for electrical connection between circuits within separate wafers or chips. There are a number of ways to create a TSV. Typically, a hole is etched into the semiconductor substrate, and sometimes through the interconnect structure as well. The hole may then be lined with various isolating layers and/or various metal layers. The hole is then filled with a conductive material, typically copper (Cu), which becomes the major part of a TSV.
In traditional technologies, an electrode electroplating method is used for the conductive filling materials to be disposed in the hole of the through silicon via (TSV), wherein a seeding layer is formed by a vacuum technique, such as plasma vapor deposition, prior to formation of the conductive filling material. The vacuum technique requires high-priced equipment, which increases device costs.